U.S. Pat. Nos. 4,329,017 and 4,479,697, the disclosures of which are hereby incorporated by reference, disclose a family of fiber optics communications modules utilizing curved, preferably spherical, imaging surfaces for coupling light between fibers, sources, and detectors. The modules utilize the advantageous properties of spherical reflectors when source and image are at closely spaced conjugate points. By using reflective, dichroic, and segmented coatings, a wide variety of devices including couplers, splitters, multiplexers, and demultiplexers may be achieved with the same basic geometry. The modules tend to be somewhat expensive, since the alignment and construction are relatively exacting processes. However, given the high performance of the modules, the price is not unreasonable. Similarly, while the modules represent an advance in miniaturization (being about 4 inches long by 1/2-inch in diameter), smaller devices are often desired. Were it possible to lower the costs by an order of magnitude or two, reduce the size, and retain the performance, the applicability of these devices could be greatly expanded.